Johnson & Johnson’s DUET program evaluating JNJ-4804, a combination of Tremfya and Simponi for inflammatory bowel disease, missed its primary endpoint for clinical remission. J&J reported that the therapy performed better than each single drug in each of two Phase 2b trials across ulcerative colitis and Crohn’s disease, but did not meet the predefined remission threshold. Investigators said J&J will continue development into late-stage testing by focusing on a subgroup approach. The result follows earlier 2022 data in which combination therapy nearly doubled remission rates and triggered competition for additional IBD combination strategies. The setback is likely to influence how sponsors structure next IBD combination trials—especially endpoint definitions, enrichment criteria, and subgroup selection.